Insulation work in house 1965

[Eisenheim]

Hello everybody

nice forum that I have been going through for several weeks by reading the different posts.

We will acquire a house in Gradignan (33170) dating from 1965 by the end of the year.
It is 70m² habitable, semi-detached on one side and like many neighboring houses with non-existent insulation, an aging heating system and old electricity (an electrician friend must also come by to tell me if there is a need to bring the standards up to full. or not ... it would be ideal).

Wishing to take advantage of the eco-loan we find out about any work to be undertaken, but before considering changing the boiler, etc, etc ... we say that good insulation would perhaps allow us to think intelligently what to choose next !!

The house was built in concrete block of 20cm thick without insulation whether it is interior or exterior. The house is on one floor with lost roof spaces (a thin layer of rock wool fights to insulate this part). The positive point is that the frames were changed 3 years ago to double glazed PVC.

In view of the DPE and the owner's consumption, the energy consumption (heating, hot water) is approximately 266kwhEP / m².year (19000kWh in hot water and heating with annual costs of 1000 €) => class E
GHG emissions are deplorable (62kgéqCO2 / m².year => class F)

I would like some advice on the solutions to consider knowing:

- I have a quote for the insulation of the lost attic with cellulose wadding (Bellouate) => 28 cm thick: 812 € TTC

- tonight I am visiting again with an insulation craftsman to get a quote on an external insulation (which he makes based on expanded polystyrene or mineral wool depending on the laying) even if I would have preferred natural wool but it is significantly more expensive from what I read.
=> the surface to be insulated would be approximately 90m² on 2 facades.

- the house does not have VMC => is it interesting to have one installed or installed?

- the boiler (Frisquet Hydromotrix 17.4kW must date from around the 90s) is in working condition but it has had its day
=> Monday, a plumber (by an acquaintance) comes to make the inventory to try to advise us as well as possible!

- the water heater for hot water is also more than 15 years old, hence the option of a condensing boiler?
=> instead of the water heater, there was a chimney flue before, would it be useful to consider installing wood heating or too complicated to implement in an old house?


In terms of priority, I saw:
1) insulation: lost roof space, exterior or interior
2) heating system: here we are a bit lost, even if we want an inexpensive solution for the environment ... brief economic :-)
3) ventilation: would a ventilation system be interesting to install?

I stop there because it is teeming with too much ... thank you in advance for your insights.

here is a front photo of the house:

[Eisenheim]

Visit of the craftsman in insulation ... the house seems to be accessible for exterior insulation (the terraced house has done exterior insulation => I have to contact the neighbors to ask them a few questions)

Quote result:
- amount of work € 12.000 (I am waiting for the paper estimate)
135m² of surface at 90 € / m²
- 12cm expanded polystyrene: wedged with "armaterm glue" + through fixing with flanged plugs
- undercoat + fiberglass frame + topcoat

What do you think ?

I went to inquire with the municipality of Gradignan concerning the possibilities of realization for exterior insulation: cladding, plaster?
I have to go back tomorrow because for the moment, they tell me that everything is possible as long as it does not distort the neighborhood too much (same wood finish)

[aerialcastor]

Hello,

To respond quickly,
Insulation from the outside is clearly the right choice.
By cons 12cm for the walls and 28cm in the attic is too little, do not hesitate to put the package, and keep the current boiler.
A wood stove is the ideal means of heating for a well insulated house with inertia.

And for DHW there is solar ...

[elephant]

I am frightened by this estimate at 90 euros / m³.

This kind of quote is not acceptable. Ask for a quote detailing the detailed price of the goods and the execution time. it really shows where the prospective supplier is going.

Always imply that other quotes are awaited ...

Always go to check wholesalers or on the internet the price of goods.

[Eisenheim]

Thank you for your reply,

- for the thickness, this is obviously the minimum to be able to benefit from the eco-loan and therefore the tax credit ==> is it really insufficient or just enough?

- the problem with the current boiler is that it is well over 15 years old with significant traces of humidity in the "laundry" space so I am waiting for the plumber's opinion on Monday to know if it is necessary consider its change !!

- for hot water it is true that there is solar, but the catch being that the chimney for the moment seems useless so I can hardly imagine the installation of a wood stove ... you no longer have to review the whole configuration of the house to allow heating, right?
Is it more profitable than installing a condensing boiler (or other)?

- and the investment in solar does not open for the eco-loan from what I see ...

[Woodcutter]

[...]
It is 70m² habitable, semi-detached on one side [...]

Is it the roof space too?

[...] Wishing to take advantage of the eco-loan we find out about any work to be undertaken, but before considering changing the boiler, etc, etc ... we say that good insulation would allow -being to think intelligently about what to choose next !!

Good thinking, knowing that the insulation is perfect for enjoying the eco-PTZ.

[...] The house was built in concrete block 20cm thick [...]
I would like some advice on the solutions to consider knowing:

[i] - I have an estimate for the insulation of the lost attic with cellulose wadding (Bellouate) => 28 cm thick: 812 € TTC

If it is a price for 70 m², I am extremely surprised !!! It is VERY inexpensive, even for Bellouate which is the cheapest wadding of the moment (but with the less good quality in return ... )

In fact, it barely offsets the cost of the material, so for me, it's clearly impossible if the cost of setting it up is included.

[...] - this evening I repeat a visit with a craftsman in insulation to have an estimate on an external insulation (which it makes based on expanded polystyrene or mineral wool according to the pose) even if I would have preferred a wool natural but it's definitely more expensive from what I read.
=> the surface to be insulated would be approximately 90m² on 2 facades.

It's unfortunately true that if you leave with materials with much better environmental impact assessments than those, disastrous, polystyrene and mineral wool, you're going to pay more, partly because of the cost of (breathable) coatings that obviously have to be redone.

[...] - the house does not have VMC => is it interesting to have one installed or to install one?

If you take care of the air tightness of your house (which is preferable for a good performance) yes it can become interesting.

[Woodcutter]

[...]
Quote result:
- amount of work € 12.000 (I am waiting for the paper estimate)
135m² of surface at 90 € / m²
- 12cm expanded polystyrene: wedged with "armaterm glue" + through fixing with flanged plugs
- undercoat + fiberglass frame + topcoat

What do you think ?

It is frankly not very expensive, even for PSE, if ALL is included (so window returns, all the little details like telephone wires, ventilation, etc.) in this price ... I have like a doubt.

[...] I went to inquire with the municipality of Gradignan concerning the possibilities of realization for the external insulations: cladding, coating?
I have to go back tomorrow because for the moment, they tell me that everything is possible as long as it does not distort the neighborhood too much (same wood finish)

Warning, good quality cladding, with natural, well-laid class 3 wood, costs 60 to 70 € / m² and cannot be fixed on polystyrene ... (it needs a supporting structure)

[Woodcutter]

[...] Always go to check with wholesalers or on the internet the price of goods.

It does nothing, if it is not exactly the same product as what is offered by the provider ...

Moreover, it is not because "on the Internet"we can find hot prices that the service provider will have the same through his usual supplier (close to his home, with whom he has an account, with whom he has good relations ...).

And finally, a "material" price does not mean much on a site if you do not know exactly the installation method and the related constraints.

In short, a bit of lost time in my opinion.

[Woodcutter]

Thank you for your reply,

- for the thickness, this is obviously the minimum to be able to benefit from the eco-loan and therefore the tax credit ==> is it really insufficient or just enough?

There are some differences between the ecoPTZ and CI requirements, but overall:
- in lost roofs, 20 cm of cotton wool is enough (R = 5.1 m².K / W)
- in walls, without thermal bridges, 10 cm of EPS are sufficient,
and again, in these calculations, we neglect the R provided by the original wall!

Now, for work (especially with cellulose wadding) that we will not repeat every 10 years, we must indeed aim for a very high level immediately ...

For me, the performance provided by the PES is sufficient for outside (R = 3.4) but for the roof, we could climb higher, especially given the low prices! (be careful, be sure to ask if it is the thickness after compaction or not!)

- for hot water it is true that there is solar, but the catch being that the chimney for the moment seems useless so I can hardly imagine the installation of a wood stove ... you no longer have to review the whole configuration of the house to allow heating, right?
Is it more profitable than installing a condensing boiler (or other)?

- and the investment in solar does not open for the eco-loan from what I see ...

If, if, it is the last box of the form:
" ❒ Hot water production equipment
using a renewable energy source
❒ Installation of a solar domestic hot water production system with CSTBât or Solar Keymark certified sensors or equivalent"

[elephant]

It does nothing, if it is not exactly the same product as what is offered by the provider ...

Moreover, it is not because "on the Internet"we can find hot prices that the service provider will have the same through his usual supplier (close to his home, with whom he has an account, with whom he has good relations ...).

And finally, a "material" price does not mean much on a site if you do not know exactly the installation method and the related constraints.

In short, a bit of lost time in my opinion.

It is part of standard building purchasing procedures in order to verify the realism of suppliers' offers, in one way or another.

We generally consider that 3 X the wholesale price (excluding VAT) is a good average ... you still need to know the wholesale price.

Pricing, ladle-wise, per m² is a detestable practice: each site has its fixed installation costs, which is expensive, it's the first m².

In any case, it is essential to meet at least 3 suppliers and obtain detailed prices. As I said before: always take your time and when possible exchange deadlines for better prices.